Common Broomrape

Firstly, many, many thanks for all the heartwarming comments, stars and hearts for my blipday - you're all such a lovely bunch! 

I've not had a chance to respond individually as Pete , Chris and I spent the Bank Holiday working on another rail-side site. I have to say it was rather wonderful - we scarcely saw another human, just lots of butterflies and flowers - though the hot, sticky weather has left me feeling rather exhausted tonight.

One of the more unusual species we saw today was Common Broomrape, which seems to be having a good year, with two sizable colonies in different parts of the site. The plants look rather weird as they have no chlorophyll, and are totally dependent on other plants for nutrients. Broomrape seeds are very small, so they can disperse widely, and remain dormant in the soil, often for many years, until stimulated to germinate by certain compounds produced by living plant roots. Broomrape seedlings put out a root-like growth, which attaches to the roots of nearby hosts. Once attached to a host, the broomrape robs its host of water and nutrients.

Some broomrapes are only able to parasitise a single plant species, but others, like this Common Broomrape, can infect several genera. At this site it is parasitic on members of the Pea family, most likely Black Medick, Hop Trefoil and White Clover. It certainly seems to be thriving, and there was no noticeable effect on the surrounding vegetation.